Convert stereo WAV to mono
Convert a stereo WAV file (2 channels) to mono by averaging the left and right channels. 100% local processing in your browser (WebAssembly) — nothing is sent to a server.
How it works
A voice memo, an interview recorded with a single microphone or a spoken podcast episode usually doesn't need to be in stereo: the left and right channels contain almost the same information, duplicated for nothing. Converting this kind of recording to mono roughly halves the file size, with no audible loss for speech, which makes it easier to send by email or archive. This tool reads each stereo WAV file, averages the left and right samples for each frame, and produces a new mono WAV file.
Why is my file rejected with an "already mono" error?
If the file you upload already has only one channel, there is nothing to convert: the tool warns you instead of producing a useless copy. Check the properties of the original file if you thought it was stereo.
Do I lose audio quality when converting to mono?
For spoken voice, the loss is practically inaudible: most of the information is identical between the two channels. For music with a deliberate stereo mix (instruments panned left/right), converting to mono flattens that spatial effect — in that case, only convert if file size is your priority.
Privacy: the conversion is calculated entirely in your browser via WebAssembly — your recordings never go through a server.